The preparations of a number of 3,5-disubstituted- and 1,3,5-trisubstituted-4-nitrosopyrazoles are described and a range of physical properties of these compounds are measured. Comparison is made with some 2,6-disubstituted nitrosobenzenes and it is shown from 13C NMR spectroscopy that the effects of substitution by flanking tert-butyl groups are moderated in the case of the pyrazoles from those in the aromatic C6 ring due to a lessening of steric hindrance. It is also suggested that steric effects are evident in the preparation of 1,3,5-substituted-4-nitrosopyrazoles when one of the flanking groups to the NO is tert-butyl or phenyl, there being no such effect for the corresponding case of the isobutyl group.
|Number of pages||4|
|Journal||Journal of the Chemical Society, Perkin Transactions 2|
|Publication status||Published - 1996|